Resveratrol attenuates the expression of HMG-CoA reductase mRNA in hamsters. Biochem Biophys Res Commun. 2008;367:190-194. [PMID: 18166149 DOI: 10.1016/j.bbrc.2007.12.140]

Effect of Resveratrol on Pregnancy, Prenatal Complications and Pregnancy-Associated Structure Alterations

Adverse pregnancy outcomes are considered significant health risks for pregnant women and their offspring during pregnancy and throughout their lifespan. These outcomes lead to a perturbated in-utero environment that impacts critical phases of the fetus's life and correlates to an increased risk of chronic pathological conditions, such as diabetes, obesity, and cardiovascular diseases, in both the mother's and adult offspring's life. The dietary intake of naturally occurring antioxidants promotes health benefits and disease prevention. In this regard, maternal dietary intake of polyphenolic antioxidants is linked to a reduced risk of maternal obesity and cardio-metabolic disorders, positively affecting both the fetus and offspring. In this work, we will gather and critically appraise the current literature highlighting the effect/s of the naturally occurring polyphenol antioxidant resveratrol on oxidative stress, inflammation, and other molecular and physiological phenomena associated with pregnancy and pregnancy conditions, such as gestational diabetes, preeclampsia, and preterm labor. The resveratrol impact on prenatal complications and pregnancy-associated structures, such as the fetus and placenta, will also be discussed. Finally, we will draw conclusions from the current knowledge and provide future perspectives on potentially exploiting resveratrol as a therapeutic tool in pregnancy-associated conditions.

Nutraceutical Approaches to Dyslipidaemia: The Main Formulative Issues Preventing Efficacy

Currently, the nutraceutical approach to treat dyslipidaemia is increasing in use, and in many cases is used by physicians as the first choice in the treatment of patients with borderline values. Nutraceuticals represent an excellent opportunity to treat the preliminary conditions not yet showing the pathological signs of dyslipidaemia. Their general safety, the patient's confidence, the convincing proof of efficacy and the reasonable costs prompted the market of new preparations. Despite this premise, many nutraceutical products are poorly formulated and do not meet the minimum requirements to ensure efficacy in normalizing blood lipid profiles, promoting cardiovascular protection, and normalizing disorders of glycemic metabolism. In this context, bioaccessibility and bioavailability of the active compounds is a crucial issue. Little attention is paid to the proper formulations needed to improve the overall bioavailability of the active molecules. According to these data, many products prove to be insufficient to ensure full enteric absorption. The present review analysed the literature in the field of nutraceuticals for the treatment of dyslipidemia, focusing on resveratrol, red yeast rice, berberine, and plant sterols, which are among the nutraceuticals with the greatest formulation problems, highlighting bioavailability and the most suitable formulations.

Effects of Resveratrol Against Induced Metabolic Syndrome in Rats: Role of Oxidative Stress, Inflammation, and Insulin Resistance

Metabolic syndrome (MS) is a serious health problem associated with an increase in risk factors for hepatic steatosis, which is the most common liver disease today. The goal of this study was to investigate the protective effects of resveratrol against metabolic alterations associated with a high-fat high-fructose diet (HFFD). Thirty-two male rats were randomly divided into four equal groups: control (cont.), metabolic syndrome (MS), resveratrol (Res), and metabolic syndrome treated with resveratrol (MS + Res). Resveratrol was administrated orally at a dose of 30 mg/kg·bw, daily. After 10 weeks, body weight, serum biochemical parameters, hepatic oxidative stress, inflammatory markers, as well as mRNA levels of hepatic genes related to lipid metabolism and insulin signaling were measured. In addition, the liver was examined histopathologically to detect lipid deposition. Increased body weight, hepatic dysfunction, dyslipidemia, hepatic insulin resistance, hepatic oxidative and inflammatory stress conditions, upregulation of mRNA expression level of sterol regulatory element binding protein 1-c (SREBP1-c), and downregulation of mRNA expression levels of peroxisome proliferated activated receptor alpha (PPARα) and insulin receptor substrate-2 (IR-S2) were all observed in the MS rats. Hepatic steatosis was confirmed by hematoxylin and eosin and Oil Red O staining. Administration of resveratrol reduced liver steatosis, oxidative stress, and inflammatory state. Also, it improved lipid profile as well as insulin sensitivity and reverted alterations in hepatic mRNA expression levels of the tested genes. Based on these findings, resveratrol could be proposed as a therapeutic approach for MS prevention.

Resveratrol protects against atherosclerosis by downregulating the PI3K/AKT/mTOR signaling pathway in atherosclerosis model mice

Atherosclerosis is a cardiovascular disease, which is characterized by the interaction between carbohydrates, lipids, cells and various other molecules and genetic factors. Previous studies have demonstrated that resveratrol (RV) served protective roles in numerous types of human disease by regulating different signaling pathways. The aim of the present study was to investigate the therapeutic effects of RV and analyze the potential RV-mediated mechanism in umbilical vein endothelial cells (UVECS) in atherosclerosis model mice. Reverse transcription-quantitative PCR, western blotting and immunohistochemistry were used to analyze the therapeutic effects of RV both in vitro and in vivo. The results demonstrated that total cholesterol, triglycerides, low-density lipoprotein cholesterin and high-density lipoprotein cholesterin levels were significantly decreased in the RV group compared with the control group. RV demonstrated significant anti-atherosclerotic activity, which was determined through the atherogenic index, 3-hydroxy-3-methyl-glutaryl-Coa (HMG-CoA) reductase activity and marker enzymes, such as lactate dehydrogenase, creatine phosphokinase, aspartate transaminase, alanine transaminase and alkaline phosphatase. It was also observed that RV treatment significantly decreased the area of the arteriosclerotic lesion in the RV group compared with the control, as well as significantly decreasing the expression levels of matrix metalloproteinase-9 and CD40 ligand (CD40L) in arterial lesion tissue compared with the control group. Serum expression levels of tumor necrosis factor-α and C-reactive protein were also significantly decreased by RV treatment compared with the control group. Furthermore, RV treatment significantly decreased the expression levels of PI3K, AKT and mTOR in UVECS in vitro. In conclusion, these results suggested that the anti-atherosclerotic activity of RV may be due to its modulatory activity over the PI3K/AKT/mTOR signaling pathway. These findings suggested a potential novel treatment option for patients with atherosclerosis.

Viral Hepatitis, Cholesterol Metabolism, and Cholesterol-Lowering Natural Compounds

Hepatitis is defined as inflammation of the liver; it can be acute or chronic. In chronic cases, the prolonged inflammation gradually damages the liver, resulting in liver fibrosis, cirrhosis, and sometimes liver failure or cancer. Hepatitis is often caused by viral infections. The most common causes of viral hepatitis are the five hepatitis viruses—hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV), and hepatitis E virus (HEV). While HAV and HEV rarely (or do not) cause chronic hepatitis, a considerable proportion of acute hepatitis cases caused by HBV (sometimes co-infected with HDV) and HCV infections become chronic. Thus, many medical researchers have focused on the treatment of HBV and HCV. It has been documented that host lipid metabolism, particularly cholesterol metabolism, is required for the hepatitis viral infection and life cycle. Thus, manipulating host cholesterol metabolism-related genes and proteins is a strategy used in fighting the viral infections. Efforts have been made to evaluate the efficacy of cholesterol-lowering drugs, particularly 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, in the treatment of hepatitis viral infections; promising results have been obtained. This review provides information on the relationships between hepatitis viruses and host cholesterol metabolism/homeostasis, as well as the discovery/development of cholesterol-lowering natural phytochemicals that could potentially be applied in the treatment of viral hepatitis.

Potential dual inhibitors of PCSK-9 and HMG-R from natural sources in cardiovascular risk management

Atherosclerotic cardiovascular disease (ASCVD) stands amongst the leading causes of mortality worldwide and has attracted the attention of world's leading pharmaceutical companies in order to tackle such mortalities. The low-density lipoprotein-cholesterol (LDL-C) is considered the most prominent biomarker for the assessment of ASCVD risk. Distinct inhibitors of 3-hydroxy-3-methyl-glutaryl-CoA reductase (HMG-R), the chief hepatic cholesterogenic enzyme, are being used since last seven decades to manage hypercholesterolemia. On the other hand, discovery and the association of proprotein convertase subtilisin/kexin type-9 (PCSK-9) with increased ASCVD risk have established PCSK-9 as a novel therapeutic target in cardiovascular medicine. PCSK-9 is well reckoned to facilitate the LDL-receptor (LDL-R) degradation and compromised LDL-C clearance leading to the arterial atherosclerotic plaque formation. The currently available HMG-R inhibitors (statins) and PCSK-9 inhibitors (siRNA, anti-sense oligonucleotides, and monoclonal antibodies) have shown great promises in achieving LDL-C lowering goals, however, their life long prescriptions have raised significant concerns. These deficits associated with the synthetic HMG-R and PCSK-9 inhibitors called for the discovery of alternative therapeutic candidates with potential dual HMG-R and PCSK-9 inhibitory activities from natural origins. Therefore, this report firstly describes the mechanistic insights into the cholesterol homeostasis through HMG-R, PCSK-9, and LDL-R functionality and then compiles the pharmacological effects of natural secondary metabolites with special emphasis on their dual HMG-R and PCSK-9 inhibitory action. In conclusion, various natural products exhibit atheroprotective effects via targeting HMG-R and PCSK-9 activities and lipoprotein metabolism, however, further clinical assessments are still warranted prior their approval for ASCVD risk management in hypercholesterolemic patients.

Resveratrol alleviates cardiac apoptosis following exposure to fenitrothion by modulating the sirtuin1/c-Jun N-terminal kinases/p53 pathway through pro-oxidant and inflammatory response improvements: In vivo and in silico studies

Fenitrothion (FNT), a commonly used organophosphate, can cause oxidative damage and apoptosis on various organs. However, the underlying mechanisms for FNT-induced cardiotoxicity did not formally report. Here, we have evaluated the possible ameliorative roles of resveratrol (RSV) against FNT-induced cardiac apoptosis in male rats through the sirtuin1 (SIRT1)/c-Jun N-terminal kinase (c-JNK)/p53 pathway concerning pro-oxidant and inflammatory cytokines. Forty-eight male rats were equally grouped into control, RSV (20 mg/kg), 5-FNT (5 mg/kg), 10-FNT (10 mg/kg), 20-FNT (20 mg/kg), 5-FNT-RSV, 10-FNT-RSV, and 20-FNT-RSV where all doses administrated by gavage for four weeks. The present findings demonstrated that RSV markedly diminished the level of hyperlipidemia and elevation in lactate dehydrogenase (LDH), total creatine kinase (CK-T), and troponin T (TnT) levels following FNT intoxication. Furthermore, RSV significantly reduced FNT-induced cardiac oxidative injury by reducing malondialdehyde (MDA) level and improving the levels of glutathione (GSH), glutathione reductase (GR), superoxide dismutase (SOD), catalase (CAT), and acetylcholinesterase (AchE). Also, the levels of interleukin-1β (IL1β,), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) were significantly attenuated in the co-treated groups. Moreover, RSV alleviated the histopathological changes promoted by FNT and repaired the transcript levels of SIRT1, c-JNK, and caspase-9/3 along with p53 immunoreactivity. In silico study revealed that the free binding energies of RSV complexes with protein and DNA sequences of SIRT1 were lower than docked complexes of FNT. Therefore, RSV reserved myocardial injury-induced apoptosis following exposure to FNT by modulating the SIRT1/c-JNK/p53 pathway through cellular redox status and inflammatory response improvements.

Nutraceuticals in the Management of Cardiovascular Risk Factors: Where is the Evidence?

Cardiovascular disease continues to rise at an alarming rate, and research focuses on possible therapies to reduce the risk and slow down its progression. Several epidemiological studies have indicated that dietary modifications, such as increased consumption of fruits and vegetables play an important role in reducing cardiovascular disease risk factors. Food sources rich in antioxidants, anti-inflammatory, hypolipidemic, and hypoglycemic properties are thought to ameliorate the progression of cardiovascular disease and serve as a potential treatment mode. Many in vivo and in vitro studies using turmeric, cinnamon, mango, blueberries, red wine, chocolate, and extra virgin olive oil have demonstrated significant improvements in cholesterol profiles, toxic reactive oxygen species, inflammation, obesity, and hypertension. In this review, we summarize recent evidence on the cardioprotective effect of different food groups, outline their potential mechanisms involved in slowing down the progression of cardiovascular disease, and highlight the beneficial effects associated with increased consumption.

Dietary Strategies to Improve Cardiovascular Health: Focus on Increasing High-Density Lipoprotein Functionality

Cardiovascular disease is one of the leading causes of morbidity and mortality worldwide, with increasing incidence. A cornerstone of cardiovascular disease prevention is lifestyle modification through dietary changes to influence various risk factors such as obesity, hypertension and diabetes. The effects of diet on cardiovascular health are complex. Some dietary components and metabolites directly affect the composition and structure of high-density lipoproteins (HDL) and increase anti-inflammatory and vasoprotective properties. HDLs are composed of distinct subpopulations of particles of varying size and composition that have several dynamic and context-dependent functions. The identification of potential dietary components that improve HDL functionality is currently an important research goal. One of the best-studied diets for cardiovascular health is the Mediterranean diet, consisting of fish, olive oil, fruits, vegetables, whole grains, legumes/nuts, and moderate consumption of alcohol, most commonly red wine. The Mediterranean diet, especially when supplemented with extra virgin olive oil rich in phenolic compounds, has been shown to markedly improve metrics of HDL functionality and reduce the burden, or even prevent the development of cardiovascular disease. Particularly, the phenolic compounds of extra virgin olive oil seem to exert the significant positive effects on HDL function. Moreover, supplementation of anthocyanins as well as antioxidants such as lycopene or the omega-3 fatty acid eicosapentaenoic acid improve parameters of HDL function. In this review, we aim to highlight recent discoveries on beneficial dietary patterns as well as nutritional components and their effects on cardiovascular health, focusing on HDL function.

A Comprehensive Analysis of the Efficacy of Resveratrol in Atherosclerotic Cardiovascular Disease, Myocardial Infarction and Heart Failure

Atherosclerosis, myocardial infarction (MI) and heart failure (HF) are the main causes of mortality and morbidity around the globe. New therapies are needed to better manage ischemic heart disease and HF as existing strategies are not curative. Resveratrol is a stilbene polyphenolic compound with favorable biological effects that counter chronic diseases. Current evidence suggests that resveratrol is cardioprotective in animal models of atherosclerosis, ischemic heart disease, and HF. Though clinical studies for resveratrol have been promising, evidence remains inadequate to introduce it to the clinical setting. In this narrative review, we have comprehensively discussed the relevant compelling evidence regarding the efficacy of resveratrol as a new therapeutic agent for the management of atherosclerosis, MI and HF.

Regulation of Apolipoprotein B by Natural Products and Nutraceuticals: A Comprehensive Review

Cardiovascular Disease (CVD) is the most important and the number one cause of mortality in both developing and industrialized nations. The co-morbidities associated with CVD are observed from infancy to old age. Apolipoprotein B100 (Apo B) is the primary apolipoprotein and structural protein of all major atherogenic particles derived from the liver including Very-Low- Density Lipoproteins (VLDL), Intermediate-density Lipoprotein (IDL), and Low-density Lipoprotein (LDL) particles. It has been suggested that measurement of the Apo B concentration is a superior and more reliable index for the prediction of CVD risk than is the measurement of LDL-C. Nutraceuticals and medicinal plants have attracted significant attention as it pertains to the treatment of non-communicable diseases, particularly CVD, diabetes mellitus, hypertension, and Nonalcoholic Fatty Liver Disease (NAFLD). The effect of nutraceuticals and herbal products on CVD, as well as some of its risk factors such as dyslipidemia, have been investigated previously. However, to the best of our knowledge, the effect of these natural products, including herbal supplements and functional foods (e.g. fruits and vegetables as either dry materials, or their extracts) on Apo B has not yet been investigated. Therefore, the primary objective of this paper was to review the effect of bioactive natural compounds on plasma Apo B concentrations. It is concluded that, in general, medicinal plants and nutraceuticals can be used as complementary medicine to reduce plasma Apo B levels in a safe, accessible, and inexpensive manner in an attempt to prevent and treat CVD.

The Role of Resveratrol in Liver Disease: A Comprehensive Review from In Vitro to Clinical Trials

Many studies have shown that resveratrol has a lot of therapeutic effects on liver disorders. Its administration can significantly increase the survival rate after liver transplantation, reduce fat deposition and ischemia-induced necrosis and apoptosis in Wistar rats. Resveratrol can provide Liver protection against chemical, cholestatic, and alcohol-mediated damage. It can improve glucose metabolism and lipid profile, reduce liver fibrosis, and steatosis. Additionally, it is capable of altering the fatty acid composition of the liver cells. Resveratrol may be a potential treatment option for the management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant, and calorie-restricting effects. There are also studies that have evaluated the effect of resveratrol on lipid and liver enzyme profiles among patients with metabolic syndrome (MetS) and related disorders. Based on the extent of liver disease worldwide and the need to find new treatment possibilities, this review critically examines current in vitro and in vivo preclinical studies and human clinical studies related to liver protection.

Pterostilbene Inhibits Dyslipidemia-Induced Activation of Progenitor Adipose Gene Under High-Fat Diet and Radiation Stressor

Repeated exposure to ionizing radiation has been reported to increase the risk of chronic metabolic disorders such as systemic hyperlipidemia and intracellular lipid accumulation that might lead to diabetes-induced heart disease. The purpose of this study was to investigate the effect of pterostilbene on high-fat diet rats suffering from ionizing radiation-induced hyperlipidemia. High-fat diet rats showed an increase in body weight and body fat compared with rats fed with normal chow. Pterostilbene and Orlistat treatments resulted in lower body weight and body fat gain, insulin resistance, reduced lipid peroxidation with attenuated liver enzyme levels, and regulated lipogenesis-related genes in the HFD + IR rat group. Regulation of Peroxisome proliferator-activated receptor-γ (PPAR-γ) mRNA enhanced paraoxonase-1 (PON-1) and arylesterase (AE) activities and inhibited that of 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMG-CoA). It also increased the activities of plasma lecithin-cholesterol acyltransferase (LCAT) and lipoprotein lipase (LPL). Pterostilbene and Orlistat also corrected the alterations of serum leptin and adiponectin levels in lipidemic rats. Such findings provide evidence that Pterostilbene and Orlistat can act as normolipidemic agents that possess lipid-lowering effects and potential as a radioprotector.

Acute oral treatment with resveratrol and Lactococcus Lactis Subsp. Lactis decrease body weight and improve liver proinflammatory markers in C57BL/6 mice

The present study aimed to evaluate the effects of resveratrol, a nutraceutical polyphenol, and Lactococcus lactis (bacteria probiotic), on metabolic parameters and hepatic proinflammatory markers expression. C57BL/6 mice were divided into 4 groups: Standard (ST), Lactococcus lactis (LL), Resveratrol (RSV), and Lactococcus lactis plus resveratrol (LL + RSV). Lactococcus lactis and resveratrol were administered by orogastric gavage. Blood parameters were assessed (total cholesterol, triglycerides, ALT and AST). IL-6 mRNA expression was evaluated by Real-time PCR and TNF-α protein expression was assessed by immunohistochemistry. The main findings showed that resveratrol and Lactococcus lactis association decreased body weight, aspartate aminotransferase and total cholesterol levels. LL and LL + RSV decreased triglycerides levels and IL-6 and TNF-α expression. These results open a perspective of using resveratrol and Lactococcus lactis to improve metabolic parameters and Lactococcus lactis in preventing inflammation and the hepatic diseases development.

Potential Herb-Drug Interactions in the Management of Age-Related Cognitive Dysfunction

Late-life mild cognitive impairment and dementia represent a significant burden on healthcare systems and a unique challenge to medicine due to the currently limited treatment options. Plant phytochemicals have been considered in alternative, or complementary, prevention and treatment strategies. Herbals are consumed as such, or as food supplements, whose consumption has recently increased. However, these products are not exempt from adverse effects and pharmacological interactions, presenting a special risk in aged, polymedicated individuals. Understanding pharmacokinetic and pharmacodynamic interactions is warranted to avoid undesirable adverse drug reactions, which may result in unwanted side-effects or therapeutic failure. The present study reviews the potential interactions between selected bioactive compounds (170) used by seniors for cognitive enhancement and representative drugs of 10 pharmacotherapeutic classes commonly prescribed to the middle-aged adults, often multimorbid and polymedicated, to anticipate and prevent risks arising from their co-administration. A literature review was conducted to identify mutual targets affected (inhibition/induction/substrate), the frequency of which was taken as a measure of potential interaction. Although a limited number of drugs were studied, from this work, interaction with other drugs affecting the same targets may be anticipated and prevented, constituting a valuable tool for healthcare professionals in clinical practice.

A Novel Promising Frontier for Human Health: The Beneficial Effects of Nutraceuticals in Cardiovascular Diseases

Cardiovascular diseases (CVDs) such as hypertension, atherosclerosis, myocardial infarction, and diabetes are a significant public health problem worldwide. Although several novel pharmacological treatments to reduce the progression of CVDs have been discovered during the last 20 years, the better way to contain the onset of CVDs remains prevention. In this regard, nutraceuticals seem to own a great potential in maintaining human health, exerting important protective cardiovascular effects. In the last years, there has been increased focus on identifying natural compounds with cardiovascular health-promoting effects and also to characterize the molecular mechanisms involved. Although many review articles have focused on the individual natural compound impact on cardiovascular diseases, the aim of this manuscript was to examine the role of the most studied nutraceuticals, such as resveratrol, cocoa, quercetin, curcumin, brassica, berberine and Spirulina platensis, on different CVDs.

Resveratrol Improves Heart Function by Moderating Inflammatory Processes in Patients with Systolic Heart Failure

The effects of resveratrol (RES) in heart failure have already been evaluated in animal models; however, in human clinical trials, they have not been confirmed yet. The aim of this study was to assess the effects of resveratrol treatment in systolic heart failure patients (heart failure with reduced ejection fraction or HFrEF). In this human clinical trial, 60 outpatients with NYHA (New York Heart Association) class II-III HFrEF were enrolled and randomized into two groups: receiving either 100-mg resveratrol daily or placebo for three months. At the beginning and at the end of the study echocardiography, a six-minute walk test, spirometry, quality of life questionnaire, lab test and RNA profile analysis were performed. The systolic and diastolic left ventricular function, as well as the global longitudinal strain, were improved significantly in the resveratrol-treated group (RES). Exercise capacity, ventilation parameters and quality of life also improved significantly in the RES group. In parallel, the cardiac biomarker levels (N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and galectin-3) decreased in the treated group. The level of inflammatory cytokines decreased significantly after RES supplementation, as a consequence of the decreased expression level of leucocyte electron transport chain proteins. The main findings of our trial are that RES treatment added to the standard heart failure therapy improved heart function and the clinical condition by moderating the inflammatory processes in patients with HFrEF.

Medicinal plants and bioactive natural compounds as inhibitors of HMG-CoA reductase: A literature review

Cardiovascular diseases (CVDs) are one of the most important causes for mortality worldwide. Elevated levels of total cholesterol, and particularly LDL-cholesterol (LDL-C) are the main risk factor for acute myocardial infarction (AMI) and ischemic heart disease. The risk of CVDs could be reduced by decreasing the elevated cholesterol levels. β-hydroxy β-methylglutaryl-CoA reductase (HMGCoAR) is the primary and rate-limiting enzyme in the cholesterol biosynthesis pathway. Recently, the crucial role of nutraceuticals in maintaining normal physiological function was established. Nutraceuticals play an important role in preventing several non-communicable diseases such as obesity, CVDs, cancer, diabetes, and reducing hyperlipidemia. Although the effect of nutraceuticals and herbal medicine on CVDs and dyslipidemia was previously investigated thoroughly, the effect of these natural products on HMGCoAR as one of the important enzymes involved in CVDs etiopathogenesis has not yet been investigated. Therefore, the major aim of this paper was to review the effects of nutraceuticals and medicinal plants on HMGCoAR. Results indicate that different types of natural foods, isolated nutrients, herbal products, and dietary supplements as nutraceuticals decrease the expression and activity of HMGCoAR. This review shows that medicinal plants and nutraceuticals could be used to decrease HMGCoAR activity as accessible and convenient and economical natural compounds to prevent dyslipidemia and CVDs.

Effect of hydroalcoholic extract of Berberis integerrima and resveratrol on ovarian morphology and biochemical parameters in Letrozole-induced polycystic ovary syndrome rat model: An experimental study

BACKGROUND

Resveratrol and Berberis integerrima (B. integerrima) are known to be natural antioxidants and regulators of human metabolism. However, the effects of resveratrol and B. integerrima on the ovarian morphology in polycystic ovary syndrome (PCOS) are not obvious.

OBJECTIVE

This study aimed to determine the effect of the hydroalcoholic extract of B. integerrima in combination with resveratrol on some biochemical parameters and ovarian morphology in the letrozole-induced PCOS rat.

MATERIALS AND METHODS

Seventy adult female Sprague-Dawley rats aged 10-12 weeks weighing 200 ± 20 gr were randomly divided into seven groups (n = 10/each). Group I): normal; Group II): vehicle; Group III): letrozole-induced PCOS 1 mg/kg letrozole orally, rats receiving 1 cc normal saline orally; Group IV): PCOS + receiving 150 mg/kg metformin orally; Group V): PCOS + receiving 20 mg/kg resveratrol orally; Group VI): PCOS + 3 gr/kg barberry orally; and Group VII): PCOS + receiving 3 gr/kg barberry and 20 mg/kg resveratrol orally. All animals were followed-up for 63 days. The biochemical parameters and histological assessments of ovaries were performed.

RESULTS

Resveratrol alone and/or in combination with B. integerrima treatment in rats led to a significant decrease in low-density lipoprotein, triglyceride, malondialdehyde, and tumor necrosis factor-alpha concentrations (p = 0.02). The groups IV, V, VI, and VII showed a decrease in insulin resistance and an increase in the superoxide dismutase, total antioxidant capacity, and high-density lipoprotein (p = 0.01). No significant difference was observed between the level of serum glucose in the treatment groups. Number of cystic follicles had a significant decrease in barberry, resveratrol, and their combination groups (p < 0.001).

CONCLUSION

Resveratrol, B. integerrima, and their combination as natural products with fewer side effects might be effective as an alternative medicine in treatment of PCOS.

Potential Effects of Antioxidant and Serum Cholesterol-Lowering Effects ofGynura bicolorWater Extracts in Syrian Hamster

Gynura bicolor(Roxb. and Willd.) DC (G. bicolor) is a dietary vegetable in the Far East. The aims of the present study were to investigate the antioxidant effects of theG. bicolorwater extract (GBWE) and its ability to regulate the blood lipid and lipoprotein profiles. In this study, the pigment composition and antioxidant ability of the GBWE were analyzed. Syrian hamsters were fed a high-fat diet (HFD) and the GBWE for 12 weeks, and the blood lipid levels, lipoprotein profiles, and cholesterol metabolism-related enzyme levels were then examined. The results showed that the GBWE exhibited excellent 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging activity and ferrous-ion-chelating ability. The hepatic glutathione levels in the hamsters were increased after the administration of low (0.4 g/kg BW, GBWE-L) or high (0.8 g/kg BW, GBWE-H) levels of the GBWE. The GBWE-H-treated hamsters exhibited significantly decreased serum levels of total cholesterols (TC) and low-density lipoprotein-cholesterol (LDL-C) and significantly increased levels of lectin-cholesterol acetyltransferase (LCAT). These results showed that GBWE-H can reduce the total cholesterol and LDL-C levels in HFD-fed hamsters, and this reduction might be involved in the regulation of LCAT expression.

Comparison Among Garlic, Berberine, Resveratrol,Hibiscus sabdariffa, GenusZizyphus, Hesperidin, Red Beetroot,Catha edulis,Portulaca oleracea, and Mulberry Leaves in the Treatment of Hypertension and Type 2 DM: A Comprehensive Review

Diabetes mellitus (DM) and hypertension are 2 of the most prevalent diseases with poor impact on health status worldwide. In most cases, they coexist with other metabolic disorders as well as cardiac, micro- and macrovascular complications. Many plants are known for their hypotensive, cardioprotective, and/or antidiabetic activities. Their active ingredients either identified and isolated or still utilized as herbal preparations of certain plant parts. The use of medicinal plants comprises the main basis for most of the traditional medicine (TM) systems and procedures. As conventional medicines seem insufficient to control such progressive diseases, herbal agents from TM could be used as adjuvant with good impact on disease control and progression as well as other concomitant health conditions. The aim of this study is to compare the efficacy of 10 different herbal medicines of botanical origin or herbal preparations in the management of hypertension and its cardiovascular complications and type 2 DM along with various coexisting health disorders. These herbal medicines are garlic, berberine, resveratrol, Hibiscus sabdariffa, Zizyphus ( oxyphylla, mucronate, jujube, rugosa), hesperidin, red beetroot, Catha edulis, mulberry leaves, and Portulaca oleracea.

Phenolic Compounds Exerting Lipid-Regulatory, Anti-Inflammatory and Epigenetic Effects as Complementary Treatments in Cardiovascular Diseases

Atherosclerosis is the main process behind cardiovascular diseases (CVD), maladies which continue to be responsible for up to 70% of death worldwide. Despite the ongoing development of new and potent drugs, their incomplete efficacy, partial intolerance and numerous side effects make the search for new alternatives worthwhile. The focus of the scientific world turned to the potential of natural active compounds to prevent and treat CVD. Essential for effective prevention or treatment based on phytochemicals is to know their mechanisms of action according to their bioavailability and dosage. The present review is focused on the latest data about phenolic compounds and aims to collect and correlate the reliable existing knowledge concerning their molecular mechanisms of action to counteract important risk factors that contribute to the initiation and development of atherosclerosis: dyslipidemia, and oxidative and inflammatory-stress. The selection of phenolic compounds was made to prove their multiple benefic effects and endorse them as CVD remedies, complementary to allopathic drugs. The review also highlights some aspects that still need clear scientific explanations and draws up some new molecular approaches to validate phenolic compounds for CVD complementary therapy in the near future.

Targeting Foam Cell Formation in Atherosclerosis: Therapeutic Potential of Natural Products

Foam cell formation and further accumulation in the subendothelial space of the vascular wall is a hallmark of atherosclerotic lesions. Targeting foam cell formation in the atherosclerotic lesions can be a promising approach to treat and prevent atherosclerosis. The formation of foam cells is determined by the balanced effects of three major interrelated biologic processes, including lipid uptake, cholesterol esterification, and cholesterol efflux. Natural products are a promising source for new lead structures. Multiple natural products and pharmaceutical agents can inhibit foam cell formation and thus exhibit antiatherosclerotic capacity by suppressing lipid uptake, cholesterol esterification, and/or promoting cholesterol ester hydrolysis and cholesterol efflux. This review summarizes recent findings on these three biologic processes and natural products with demonstrated potential to target such processes. Discussed also are potential future directions for studying the mechanisms of foam cell formation and the development of foam cell-targeted therapeutic strategies.

Mediterranean products as promising source of multi-target agents in the treatment of metabolic syndrome

Alteration of nutritional habits play an essential role on the risk of developing Metabolic Syndrome (MetS). Several epidemiological studies have shown that assuming diets rich of foods included in the Mediterranean diet (MetDiet) pattern like, such as olive oil, nuts, fruit, fiber, vegetables, wine and grain cereals has protective effects on the different risk factors characterizing the MetS. The beneficial effects of the MetDiet in the MetS are mainly due to the antioxidant and anti-inflammatory properties of the most abundant phytochemical components of such foods as polyphenols like resveratrol and oleuropein, allyl sulfides, ellagic acid, mono- and poly-unsaturated fatty acids (MUFA and PUFA), tocopherols and flavonoids like quercetin, which have shown positive results in the prevention of cardiovascular diseases (CVDs), with related risk factors, like hypertension, hypercholesterolemia and obesity. In this review, we highlighted the multi-target activities of the bioactive components contained in some foods typical of the Mediterranean area like olive oil, onion, liquorice, rosemary, oregano, hazelnut, pistachio, "Melannurca" apple, red wine, hot pepper, Citrus sp. fruits, saffron and garlic, with particular focus on their impact on health outcomes in relation to MetS main key factors, such as insulin resistance (IR) and type 2 diabetes mellitus (T2DM), endothelial dysfunctions, inflammatory response, oxidative stress and dyslipidaemic and hypercholesterolemic effects.

The Fluid Aspect of the Mediterranean Diet in the Prevention and Management of Cardiovascular Disease and Diabetes: The Role of Polyphenol Content in Moderate Consumption of Wine and Olive Oil

A growing interest has emerged in the beneficial effects of plant-based diets for the prevention of cardiovascular disease, diabetes and obesity. The Mediterranean diet, one of the most widely evaluated dietary patterns in scientific literature, includes in its nutrients two fluid foods: olive oil, as the main source of fats, and a low-to-moderate consumption of wine, mainly red, particularly during meals. Current mechanisms underlying the beneficial effects of the Mediterranean diet include a reduction in inflammatory and oxidative stress markers, improvement in lipid profile, insulin sensitivity and endothelial function, as well as antithrombotic properties. Most of these effects are attributable to bioactive ingredients including polyphenols, mono- and poly-unsaturated fatty acids. Polyphenols are a heterogeneous group of phytochemicals containing phenol rings. The principal classes of red wine polyphenols include flavonols (quercetin and myricetin), flavanols (catechin and epicatechin), anthocyanin and stilbenes (resveratrol). Olive oil has at least 30 phenolic compounds. Among them, the main are simple phenols (tyrosol and hydroxytyrosol), secoroids and lignans. The present narrative review focuses on phenols, part of red wine and virgin olive oil, discussing the evidence of their effects on lipids, blood pressure, atheromatous plaque and glucose metabolism.

A Unique Formulation of Cardioprotective Bio-Actives: An Overview of Their Safety Profile

The burden of cardiovascular disease (CVD) remains high globally and in the United States despite the availability of pharmaceuticals aimed at its prevention and treatment. An invention by Summit Innovation Labs, which is a formula consisting of a unique blend of select polyphenols (i.e., curcumin, quercetin, resveratrol), vitamin K2 as menaquinone-7, and magnesium, was recently developed to modulate the impact of the specific drivers of CVD, namely, vascular calcification, oxidative stress, and chronic inflammation. The SIL formulation is a dietary supplement that was designed leveraging the more bioavailable forms of ingredients with poor absorption, such as curcumin and quercetin. Each ingredient within the SIL formulation has been shown to contribute to CVD risk reduction by moderating the effect of CVD triggers, thereby providing a holistic prevention strategy for CVD in the healthy population. This review focuses on recently published clinical data to support the safety profile of these ingredients following oral administration. The preponderance of clinical trial data reviewed support the overall safety of the bioactives when used singly or in combination. The most commonly reported adverse effects were generally mild dose-related gastrointestinal disturbances, which may be alleviated with diet in some cases. In light of these, we conclude that the combination of the ingredients in the SIL formulation is reasonably expected to be safe.

Long-term effects of maternal resveratrol intake during lactation on cholesterol metabolism in male rat offspring

Resveratrol (RSV) can protect against non-communicable diseases by improving cholesterol metabolism. However, it is unclear that effects of maternal RSV intake on health of adult offspring. In this study, we examined effects of maternal RSV intake during lactation on cholesterol metabolism in adult male rat offspring. Female Wistar rats were fed a control diet (CON) supplemented with or without RSV (20 mg/kg body weight/day) during their lactation period. Male offspring were weaned onto a standard diet and maintained on this diet for 36 weeks. As a result, plasma cholesterol level significantly decreased in RSV offspring compared to CON offspring. Furthermore, a decrease in hepatic 3-hydroxy-3-methylglutaryl-CoA reductase level and an increase in hepatic LDL-receptor level were observed in the RSV offspring. These results indicate that maternal RSV intake causes long-term decrease in plasma cholesterol level in the offspring through suppression of hepatic cholesterol biosynthesis and promotion of hepatic cholesterol uptake.

Dietary natural products as emerging lipoprotein(a)-lowering agents

Elevated plasma lipoprotein(a) (Lp(a)) levels are associated with an increased risk of cardiovascular disease (CVD). Hitherto, niacin has been the drug of choice to reduce elevated Lp(a) levels in hyperlipidemic patients but its efficacy in reducing CVD outcomes has been seriously questioned by recent clinical trials. Additional drugs may reduce to some extent plasma Lp(a) levels but the lack of a specific therapeutic indication for Lp(a)-lowering limits profoundly reduce their use. An attractive therapeutic option is natural products. In several preclinical and clinical studies as well as meta-analyses, natural products, including l-carnitine, coenzyme Q ₁₀ , and xuezhikang were shown to significantly decrease Lp(a) levels in patients with Lp(a) hyperlipoproteinemia. Other natural products, such as pectin, Ginkgo biloba, flaxseed, red wine, resveratrol and curcuminoids can also reduce elevated Lp(a) concentrations but to a lesser degree. In conclusion, aforementioned natural products may represent promising therapeutic agents for Lp(a) lowering.

Resveratrol: A miraculous natural compound for diseases treatment

Resveratrol (3, 5, 4'-trihydroxystilbene) is a nonflavonoid polyphenol that naturally occurs as phytoalexin. It is produced by plant sources such as grapes, apples, blueberries, plums, and peanut. This compound has critical roles in human health and is well known for its diverse biological activities such as antioxidant and anti-inflammatory properties. Nowadays, due to rising incidence of different diseases such as cancer and diabetes, efforts to find novel and effective disease-protective agents have led to the identification of plant-derived compounds such as resveratrol. Furthermore, several in vitro and in vivo studies have revealed the effectiveness of resveratrol in various diseases such as diabetes mellitus, cardiovascular disease, metabolic syndrome, obesity, inflammatory, neurodegenerative, and age-related diseases. This review presents an overview of currently available studies on preventive properties and essential molecular mechanisms involved in various diseases.

Catalase and nonalcoholic fatty liver disease

Obesity and insulin resistance are considered the main causes of nonalcoholic fatty liver disease (NAFLD), and oxidative stress accelerates the progression of NAFLD. Free fatty acids, which are elevated in the liver by obesity or insulin resistance, lead to incomplete oxidation in the mitochondria, peroxisomes, and microsomes, leading to the production of reactive oxygen species (ROS). Among the ROS generated, H₂O₂ is mainly produced in peroxisomes and decomposed by catalase. However, when the H₂O₂ concentration increases because of decreased expression or activity of catalase, it migrates to cytosol and other organelles, causing cell injury and participating in the Fenton reaction, resulting in serious oxidative stress. To date, numerous studies have been shown to inhibit the pathogenesis of NAFLD, but treatment for this disease mainly depends on weight loss and exercise. Various molecules such as vitamin E, metformin, liraglutide, and resveratrol have been proposed as therapeutic agents, but further verification of the dose setting, clinical application, and side effects is needed. Reducing oxidative stress may be a fundamental method for improving not only the progression of NAFLD but also obesity and insulin resistance. However, the relationship between NAFLD progression and antioxidants, particularly catalase, which is most commonly expressed in the liver, remains unclear. Therefore, this review summarizes the role of catalase, focusing on its potential therapeutic effects in NAFLD progression.

Co-administrating apigenin in a high-cholesterol diet prevents hypercholesterolaemia in golden hamsters

Objectives

Hypercholesterolaemia is a major risk factor for developing atherosclerosis. Increased consumption of fruits and vegetables is recommended to hypercholesterolaemic patients. In this study, the hypocholesterolaemic effect of apigenin and luteolin was evaluated in a hamster model.

Methods

Hamsters were put on a high-cholesterol diet for 9 weeks, and apigenin or luteolin was administered in the diet at 60 and 300 ppm.

Key findings

Both apigenin and luteolin supplementations could attenuate the aorta plaque formation by 30% and 20%, respectively. Apigenin-fed hamsters at both dosages displayed a 1.5-fold increase in hepatic Ldlr expression and a 40% reduction in non-HDL cholesterol level as compared with those in the control fed a high-cholesterol (HC) diet. Besides, faecal elimination of cholesterol was facilitated by 20% in the hamsters with high apigenin consumption. Suppressing the expression of the cholesterol transporter ncp1l1 in the intestinal mucosa could block the cholesterol absorption and promote its elimination. The differential regulations of ncp1l1 and Ldlr appeared to be the underlying hypocholesterolaemic mechanism of apigenin in this model system. Luteolin supplementation, on the other hand, had no effect on the blood cholesterol.

Conclusions

This study illustrated that dietary administration of apigenin attenuated HC feeding-induced hypercholesterolemia in hamsters.

Anticancer properties of tocotrienols: A review of cellular mechanisms and molecular targets

Vitamin E is composed of two groups of compounds: α-, β-, γ-, and δ-tocopherols (TPs), and the corresponding unsaturated tocotrienols (TTs). TTs are found in natural sources such as red palm oil, annatto seeds, and rice bran. In the last decades, TTs (specifically, γ-TT and δ-TT) have gained interest due to their health benefits in chronic diseases, based on their antioxidant, neuroprotective, cholesterol-lowering, anti-inflammatory activities. Several in vitro and in vivo studies pointed out that TTs also exert a significant antitumor activity in a wide range of cancer cells. Specifically, TTs were shown to exert antiproliferative/proapoptotic effects and to reduce the metastatic or angiogenic properties of different cancer cells; moreover, these compounds were reported to specifically target the subpopulation of cancer stem cells, known to be deeply involved in the development of resistance to standard therapies. Interestingly, recent studies pointed out that TTs exert a synergistic antitumor effect on cancer cells when given in combination with either standard antitumor agents (i.e., chemotherapeutics, statins, "targeted" therapies) or natural compounds with anticancer activity (i.e., sesamin, epigallocatechin gallate (EGCG), resveratrol, ferulic acid). Based on these observations, different TT synthetic derivatives and formulations were recently developed and demonstrated to improve TT water solubility and to reduce TT metabolism in cancer cells, thus increasing their biological activity. These promising results, together with the safety of TT administration in healthy subjects, suggest that these compounds might represent a new chemopreventive or anticancer treatment (i.e., in combination with standard therapies) strategy. Clinical trials aimed at confirming this antitumor activity of TTs are needed.

Effects of resveratrol on memory performance, hippocampus connectivity and microstructure in older adults - A randomized controlled trial

INTRODUCTION

The polyphenol resveratrol has been suggested to exert beneficial effects on memory and the aging hippocampus due to calorie-restriction mimicking effects. However, the evidence based on human interventional studies is scarce. We therefore aimed to determine the effects of resveratrol on memory performance, and to identify potential underlying mechanisms using a broad array of blood-based biomarkers as well as hippocampus connectivity and microstructure assessed with ultra-high field magnetic resonance imaging (UHF-MRI).

METHODS

In this double-blind, randomized controlled trial, 60 elderly participants (60-79 years) with a wide body-mass index (BMI) range of 21-37 kg/m² were randomized to receive either resveratrol (200 mg/day) or placebo for 26 weeks (registered at ClinicalTrials.gov: NCT02621554). Baseline and follow-up assessments included the California Verbal Learning Task (CVLT, main outcome), the ModBent task, anthropometry, markers of glucose and lipid metabolism, inflammation and neurotrophins derived from fasting blood, multimodal neuroimaging at 3 and 7 T, and questionnaires to assess confounding factors.

RESULTS

Multivariate repeated-measures ANOVA did not detect significant time by group effects for CVLT performance. There was a trend for preserved pattern recognition memory after resveratrol, while performance decreased in the placebo group (n.s., p = 0.07). Further exploratory analyses showed increases in both groups over time in body fat, cholesterol, fasting glucose, interleukin 6, high sensitive C-reactive protein, tumor necrosis factor alpha and in mean diffusivity of the subiculum and presubiculum, as well as decreases in physical activity, brain-derived neurotrophic factor and insulin-like growth factor 1 at follow-up, which were partly more pronounced after resveratrol.

DISCUSSION

This interventional study failed to show significant improvements in verbal memory after 6 months of resveratrol in healthy elderly with a wide BMI range. A non-significant trend emerged for positive effects on pattern recognition memory, while possible confounding effects of unfavorable changes in lifestyle behavior, neurotrophins and inflammatory markers occurred. Our findings also indicate the feasibility to detect (un)healthy aging-related changes in measures of hippocampus microstructure after 6 months using 7T diffusion MRI. More studies incorporating a longer duration and larger sample size are needed to determine if resveratrol enhances memory performance in healthy older adults.

Functional foods and dietary supplements for the management of dyslipidaemia

Dyslipidaemia is characterized by increased blood levels of total or LDL cholesterol and triglycerides, or decreased HDL cholesterol levels, and is a risk factor for cardiovascular disease. Dyslipidaemia has a high worldwide prevalence, and many patients are turning to alternatives to pharmacotherapy to manage their lipid levels. Lifestyle modification should be emphasized in all patients to reduce cardiovascular risk and can be initiated before pharmacotherapy in primary prevention of cardiovascular disease. Many functional foods and natural health products have been investigated for potential lipid-lowering properties. Those with good evidence for a biochemical effect on plasma lipid levels include soy protein, green tea, plant sterols, probiotic yogurt, marine-derived omega-3 fatty acids and red yeast rice. Other products such as seaweed, berberine, hawthorn and garlic might confer some limited benefit in certain patient groups. Although none of these products can reduce lipid levels to the same extent as statins, most are safe to use in addition to other lifestyle modifications and pharmacotherapy. Natural health products marketed at individuals with dyslipidaemia, such as policosanol, guggulsterone and resveratrol, have minimal definitive evidence of a biochemical benefit. Additional research is required in this field, which should include large, high-quality randomized controlled trials with long follow-up periods to investigate associations with cardiovascular end points.

Synthesis, antiplatelet and antithrombotic activities of resveratrol derivatives with NO-donor properties

Resveratrol (RVT) is a stilbene with a protective effect on the cardiovascular system; however, drawbacks including low bioavailability and fast metabolism limit its efficacy. In this work we described new resveratrol derivatives with nitric oxide (NO) release properties, ability to inhibit platelet aggregation and in vivo antithrombotic effect. Compounds (4a-f) were able to release NO in vitro, at levels ranging from 24.1% to 27.4%. All compounds (2a-f and 4a-f) have exhibited platelet aggregation inhibition using as agonists ADP, collagen and arachidonic acid. The most active compound (4f) showed reduced bleeding time compared to acetylsalicylic acid (ASA) and protected up to 80% against in vivo thromboembolic events. These findings suggest that hybrid resveratrol-furoxan (4f) is a novel lead compound able to prevent platelet aggregation and thromboembolic events.

Resveratrol and pterostilbene attenuated smokeless tobacco induced cardiovascular aberrations in estrogen deficient female rats

This study evaluated the impact of resveratrol (RSV) and pterostilbene (PT) on the aqueous extract of smokeless tobacco (AEST) induced cardiovascular aberrations in estrogen deficient female Sprague-Dawley rats. Exposure to 4-vinylcyclohexene diepoxide (VCD) (80 mg kg-1, i.p.) for 30 days induces estrogen deficiency. The rats were administered AEST alone or AEST along with resveratrol and/or pterostilbene. Several markers of cardiovascular health were estimated to evaluate the repercussion of the exposures. RSV and PT per se and in combination significantly reversed the derangements caused by AEST. RSV decreased the atherogenic index and systolic blood pressure and normalized ECG. RSV and PT treatment markedly decreased aortic collagen, cardiac-carbonylated proteins, serum creatine-kinase, cholesterol, LDH, LDL, VLDL, CRP and TNF-α levels. Conversely, they increased serum nitrate-nitrite and HDL levels. The drugs improved the gene expression of SIRT1, PGC-1α, PPAR-α, TFAM, NRF-1 and mtDNA in the cardiac tissue. However, the expression of SIRT1 was not modified by PT. These favorable effects were comparable to those of estradiol therapy. Histopathological outcomes also corroborated these benefits. Thus, resveratrol and pterostilbene abrogated the deleterious effects of AEST on cardiovascular parameters in estrogen deficient female rats.

Synergistic Anticancer Effect of Tocotrienol Combined with Chemotherapeutic Agents or Dietary Components: A Review

Tocotrienol (T3), unsaturated vitamin E, is gaining a lot of attention owing to its potent anticancer effect, since its efficacy is much greater than that of tocopherol (Toc). Various factors are known to be involved in such antitumor action, including cell cycle arrest, apoptosis induction, antiangiogenesis, anti-metastasis, nuclear factor-κB suppression, and telomerase inhibition. Owing to a difference in the affinity of T3 and Toc for the α-tocopherol transfer protein, the bioavailability of orally ingested T3 is lower than that of Toc. Furthermore, cellular uptake of T3 is interrupted by coadministration of α-Toc in vitro and in vivo. Based on this, several studies are in progress to screen for molecules that can synergize with T3 in order to augment its potency. Combinations of T3 with chemotherapeutic drugs (e.g., statins, celecoxib, and gefitinib) or dietary components (e.g., polyphenols, sesamin, and ferulic acid) exhibit synergistic actions on cancer cell growth and signaling pathways. In this review, we summarize the current status of synergistic effects of T3 and an array of agents on cancer cells, and discuss their molecular mechanisms of action. These combination strategies would encourage further investigation and application in cancer prevention and therapy.

EFFECTS OF RESVERATROL ON LIVER FUNCTION OF OBESE FEMALE WISTAR RATS

Abstract Resveratrol has antioxidant, anti-inflammatory, lipolytic, and antifibrotic properties, which may be useful in supplementation of obese patients and with liver problems. This study evaluated the effects of 6-week resveratrol supplementation on the lipid profile and liver function of female Wistar rats fed a high-fat diet to induce obesity. Sixty-four Wistar rats were divided into 4 groups (n = 16): the control group (C); the control obese group (CO); the resveratrol group (R); and the resveratrol obese group (RO). At the end of the experiment, the animals were anesthetized for blood collection and subsequent euthanasia for collection of liver biopsy. The parameters for body weight, liver weight, retroperitoneal fat weight, serum lipid and liver profiles and histopathological analysis were evaluated. The 6-week resveratrol administration did not induce weight loss nor did it reduce the lipid profile; however, it decreased the liver enzymes aspartate aminotransferase (AST) and alkaline phosphatase (ALP) and reduced the incidence of steatosis (75.0%) in group RO compared with group CO (81.2%). Thus, we concluded that resveratrol supplementation for the short period of six weeks had a beneficial effect on liver function by reducing hepatic steatosis and the liver enzymes AST and ALP in obese female rats.

Herbal medicines and nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD), which is characterized by excessive fat accumulation in the liver of patients who consume little or no alcohol, becomes increasingly common with rapid economic development. Long-term excess fat accumulation leads to NAFLD and represents a global health problem with no effective therapeutic approach. NAFLD is considered to be a series of complex, multifaceted pathological processes involving oxidative stress, inflammation, apoptosis, and metabolism. Over the past decades, herbal medicines have garnered growing attention as potential therapeutic agents to prevent and treat NAFLD, due to their high efficacy and low risk of side effects. In this review, we evaluate the use of herbal medicines (including traditional Chinese herbal formulas, crude extracts from medicinal plants, and pure natural products) to treat NAFLD. These herbal medicines are natural resources that can inform innovative drug research and the development of treatments for NAFLD in the future.

Resveratrol and Cardiovascular Diseases

The increased incidence of cardiovascular diseases (CVDs) has stimulated research for substances that could improve cardiovascular health. Among them, resveratrol (RES), a polyphenolic compound notably present in grapes and red wine, has been involved in the “French paradox”. RES is known for its antioxidant and anti-inflammatory properties and for its ability to upregulate endothelial NO synthase (eNOS). RES was able to scavenge ^•OH/O₂^•− and peroxyl radicals, which can limit the lipid peroxidation processes. Moreover, in bovine aortic endothelial cells (BAEC) under glucose-induced oxidative stress, RES restored the activity of dimethylargininedimethylaminohydrolase (DDAH), an enzyme that degrades an endogenous inhibitor of eNOS named asymmetric dimethylarginine (ADMA). Thus, RES could improve ^•NO availability and decrease the endothelial dysfunction observed in diabetes. Preclinical studies have made it possible to identify molecular targets (SIRT-1, AMPK, Nrf2, NFκB…); however, there are limited human clinical trials, and difficulties in the interpretation of results arise from the use of high-dose RES supplements in research studies, whereas low RES concentrations are present in red wine. The discussions on potential beneficial effects of RES in CVDs (atherosclerosis, hypertension, stroke, myocardial infarction, heart failure) should compare the results of preclinical studies with those of clinical trials.

Grapes (Vitis vinifera) as a Potential Candidate for the Therapy of the Metabolic Syndrome

Metabolic syndrome is associated with several disorders, including hypertension, diabetes, hyperlipidemia as well as cardiovascular diseases and stroke. Plant-derived polyphenols, compounds found in numerous plant species, play an important role as potential treatments for components of metabolic syndrome. Studies have provided evidence for protective effects of various polyphenol-rich foods against metabolic syndrome. Fruits, vegetables, cereals, nuts, and berries are rich in polyphenolic compounds. Grapes (Vitis vinifera), especially grape seeds, stand out as rich sources of polyphenol potent antioxidants and have been reported helpful for inhibiting the risk factors involved in the metabolic syndrome such as hyperlipidemia, hyperglycemia, and hypertension. There are also many studies about gastroprotective, hepatoprotective, and anti-obesity effects of grape polyphenolic compounds especially proanthocyanidins in the literature. The present study investigates the protective effects of grape seeds in metabolic syndrome. The results of this study show that grape polyphenols have significant effects on the level of blood glucose, lipid profile, blood pressure, as well as beneficial activities in liver and heart with various mechanisms. In addition, the pharmacokinetics of grape polyphenols is discussed. More detailed mechanistic investigations and phytochemical studies for finding the exact bioactive component(s) and molecular signaling pathways are suggested.

Natural antioxidants for non-alcoholic fatty liver disease: molecular targets and clinical perspectives

Non-alcoholic steatohepatitis (NASH), the progressive form of non-alcoholic fatty liver disease (NAFLD), is emerging as a main health problem in industrialized countries. Lifestyle modifications are effective in the treatment of NAFLD; however, the long-term compliance is low. Therefore, several pharmacological treatments have been proposed but none has shown significant efficacy or long-term safety. Natural polyphenols are a heterogeneous class of polyphenolic compounds contained in vegetables, which are being proposed for the treatment of different metabolic disorders. Although the beneficial effect of these compounds has traditionally related to their antioxidant properties, they also exert several beneficial effects on hepatic and extra-hepatic glucose and lipid homeostasis. Furthermore, natural polyphenols exert antifibrogenic and antitumoural effects in animal models, which appear relevant from a clinical point of view because of the association of NASH with cirrhosis and hepatocellular carcinoma. Several polyphenols, such anthocyanins, curcumin and resveratrol and those present in coffee, tea, soy are available in the diet and their consumption can be proposed as part of a healthy diet for the treatment of NAFLD. Other phenolic compounds, such as silymarin, are commonly consumed worldwide as nutraceuticals or food supplements. Natural antioxidants are reported to have beneficial effects in preclinical models of NAFLD and in pilot clinical trials, and thus need clinical evaluation. In this review, we summarize the existing evidence regarding the potential role of natural antioxidants in the treatment of NAFLD and examine possible future clinical applications.

Ovarian actions of resveratrol

Resveratrol, a natural polyphenol found in grapes, berries, and medicinal plants, exhibits antioxidant and anti-inflammatory activities and has been proposed to be a longevity-prolonging agent. There is also growing evidence that resveratrol has cardioprotective properties and beneficial effects on both glucose and lipid metabolism. Recently, several studies have examined the use of resveratrol as a therapeutic agent to treat numerous pathological and metabolic disorders. Herein, we present insights into the mechanisms of action, biological effects, and current evidence of actions of resveratrol on the ovary. In vitro, resveratrol inhibits proliferation and androgen production by theca-interstitial cells. Resveratrol also exerts a cytostatic, but not cytotoxic, effect on granulosa cells, while decreasing aromatization and vascular endothelial growth factor expression. In vivo, resveratrol treatment reduced the size of adipocytes and improved estrus cyclicity in the previously acyclic rat model of polycystic ovary syndrome (PCOS). In addition, resveratrol increased the ovarian follicular reserve and prolonged the ovarian life span in rats. Taken together, resveratrol emerges as a potential therapeutic agent to treat conditions associated with androgen excess, such as PCOS. The efficacy of resveratrol in the treatment of gynecological conditions requires further investigation.

Potential of tocotrienols in the prevention and therapy of Alzheimer's disease

Currently there is no cure for Alzheimer's disease (AD); clinical trials are underway to reduce amyloid generation and deposition, a neuropathological hallmark in brains of AD patients. While genetic factors and neuroinflammation contribute significantly to AD pathogenesis, whether increased cholesterol level is a causative factor or a result of AD is equivocal. Prenylation of proteins regulating neuronal functions requires mevalonate-derived farnesyl pyrophosphate (FPP) and geranylgeranyl pyrophosphate (GGPP). The observation that the levels of FPP and GGPP, but not that of cholesterol, are elevated in AD patients is consistent with the finding that statins, competitive inhibitors of 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase, reduce FPP and GGPP levels and amyloid β protein production in preclinical studies. Retrospective studies show inverse correlations between incidence of AD and the intake and serum levels of the HMG CoA reductase-suppressive tocotrienols; tocopherols show mixed results. Tocotrienols, but not tocopherols, block the processing and nuclear localization of sterol regulatory element binding protein-2, the transcriptional factor for HMG CoA reductase and FPP synthase, and enhance the degradation of HMG CoA reductase. Consequently, tocotrienols deplete the pool of FPP and GGPP and potentially blunt prenylation-dependent AD pathogenesis. The antiinflammatory activity of tocotrienols further contributes to their protection against AD. The mevalonate- and inflammation-suppressive activities of tocotrienols may represent those of an estimated 23,000 mevalonate-derived plant secondary metabolites called isoprenoids, many of which are neuroprotective. Tocotrienol-containing plant foods and tocotrienol derivatives and formulations with enhanced bioavailability may offer a novel approach in AD prevention and treatment.

Resveratrol and anti-atherogenic effects

The role of inflammation and oxidative stress in atherosclerosis development has been increasingly well recognized over the past decade. Inflammation has a significant role at all stages of atherosclerosis, including initiation, progression and plaque formation. Resveratrol is a naturally occurring polyphenolic compound found in grape products, berry fruits and red wine. Its ability to behave therapeutically as a component of red wine has attracted wide attention. Accumulating evidence suggests that it is a highly pleiotropic molecule that modulates numerous targets and molecular functions. Epidemiological studies indicate that the Mediterranean diet, rich in resveratrol, is associated with a reduced risk of atherosclerosis. Resveratrol is believed to decrease circulating low-density lipoprotein cholesterol levels, reduce cardiovascular disease risk; it reduces lipid peroxidation, platelet aggregation and oxidative stress. Resveratrol is considered a safe compound, since no significant toxic effects have been demonstrated after administration of a broad range of concentrations, and an effective anti-atherogenic agent.